Milk contains many bioactive compounds with health benefits beyond simple nutrition. This chapter provides a comprehensive review of bioactives in milk and research on their nutraceutical properties. These include bioactive proteins such as caseins, whey proteins such as α-lactalbumin and β-lactoglobulin and enzymes such as lactoperoxidase and lysozyme. The chapter then reviews bioactive peptides with antihypertensive, antioxidative peptides, antithrombotic and other therapeutic properties before going on to cover bioactive lipids such as conjugated linoleic acid (CLA), phospholipids and cholesterol. It concludes by discussing bioactive arbohydrates such as lactose and oligosaccharides, other bioactive compounds such as growth factors, cytokines, polyamines, nucleosides and nucleotides as well as bioactive minerals and vitamins.